Sword finger offer 41. median in data flow

The finger of the sword Offer 41. Median in data stream https://leetcode.cn/problems/shu-ju-liu-zhong-de-zhong-wei-shu-lcof/

Violent solution , Every time I look up , Just sort them all

class MedianFinder:

    def __init__(self):
        self.res=[]


    def addNum(self, num):
        self.res.append(num)

    def findMedian(self):
        l=len(self.res)
        self.res.sort()
        if l%2:
            return self.res[l//2]
        else:
            return (self.res[l//2]+self.res[l//2-1])/2

  Big pile top , Small top pile method .

First of all, understand the following articles

Python heapq Introduction to the usage of Library _ Brother Xiaobin ge The blog of -CSDN Blog _heapq pythonhttps://blog.csdn.net/weixin_43790276/article/details/107741332

 Python There is no big top pile , What shall I do? ？

Then take all the numbers as their opposite numbers , such , You can use a small top pile .

from heapq import *

class MedianFinder:
    def __init__(self):
        self.A = [] #  Small cap pile , Save the larger half 
        self.B = [] #  Big pile top , Save the smaller half 

    def addNum(self, num: int) -> None:
        if len(self.A) != len(self.B):
            heappush(self.A, num)
            heappush(self.B, -heappop(self.A))
        else:
            heappush(self.B, -num)
            heappush(self.A, -heappop(self.B))

    def findMedian(self) -> float:
        return self.A[0] if len(self.A) != len(self.B) else (self.A[0] - self.B[0]) / 2.0

 author ：jyd
 link ：https://leetcode.cn/problems/shu-ju-liu-zhong-de-zhong-wei-shu-lcof/solution/mian-shi-ti-41-shu-ju-liu-zhong-de-zhong-wei-shu-y/
 source ： Power button （LeetCode）
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